package org.stvd.common.security.support;

import java.util.Collection;
import java.util.Iterator;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.security.access.AccessDecisionManager;
import org.springframework.security.access.AccessDeniedException;
import org.springframework.security.access.ConfigAttribute;
import org.springframework.security.authentication.InsufficientAuthenticationException;
import org.springframework.security.core.Authentication;
import org.springframework.security.core.GrantedAuthority;

public class ResourceAccessDecisionManager implements AccessDecisionManager {

    private Logger logger = LoggerFactory.getLogger(getClass());
    
    public void decide(Authentication authentication, Object object, Collection<ConfigAttribute> configAttributes)
            throws AccessDeniedException, InsufficientAuthenticationException {
        if (configAttributes == null) {
            return;
        }
        // 所请求的资源拥有的权限(一个资源对多个权限)
        Iterator<ConfigAttribute> iterator = configAttributes.iterator();
        while (iterator.hasNext()) {
            ConfigAttribute configAttribute = iterator.next();
            // 访问所请求资源所需要的权限
            String needPermission = configAttribute.getAttribute();
//            System.out.println("needPermission is " + needPermission);
            // 用户所拥有的权限authentication
            for (GrantedAuthority ga : authentication.getAuthorities()) {
                if (needPermission.equals(ga.getAuthority())) {
                    logger.info("    Request user is "+authentication.getName()+authentication.getAuthorities()+
                            ",allow!");
                    return;
                }
            }
        }
        // 没有权限
        logger.info("    Request user is "+authentication.getName()+authentication.getAuthorities()+",denied!");
        throw new AccessDeniedException("不允许访问");
    }

    public boolean supports(ConfigAttribute attribute) {
        return true;
    }

    public boolean supports(Class<?> clazz) {
        return true;
    }

}
